The Chamaeleon i dark cloud (Cha i) has been
mapped in
with an angular resolution of using the
SEST telescope. The large scale structures previously observed with lower
spatial resolution in the
cloud turn into a network of clumpy filaments. The automatic
Clumpfind routine developed by [CITE] is used to identify
individual clumps in a consistent way. Altogether 71 clumps were found and
the total mass of these clumps is 230 . The dense “cores” detected
with the NANTEN telescope ([CITE]) and the very cold cores
detected in the ISOPHOT serendipity survey ([CITE]) form
parts of these filaments but decompose into numerous “clumps”. The
filaments are preferentially oriented at right angles to the
large-scale magnetic field in the region. We discuss the cloud
structure, the physical characteristics of the clumps and the
distribution of young stars. The observed clump mass spectrum is
compared with the predictions of the turbulent fragmentation model of
[CITE]. Agreement is found if fragmentation has been
driven by very large-scale hypersonic turbulence, and if by now it has had
time to dissipate into modestly supersonic turbulence in the
interclump gas. According to numerical
simulations, large-scale turbulence should have resulted in
filamentary structures as seen in Cha i. The well-oriented
magnetic field does not, however, support this picture, but
suggests magnetically steered large-scale collapse. The origin of
filaments and clumps in Cha i is thus controversial. A possible
solution is that the characterization of the driving turbulence fails
and that in fact different processes have been effective on small and large
scales in this cloud.

Current usage metrics show cumulative count of Article Views (full-text article views including HTML views, PDF and ePub downloads, according to the available data) and Abstracts Views on Vision4Press platform.

Data correspond to usage on the plateform after 2015. The current usage metrics is available 48-96 hours after online publication and is updated daily on week days.